The role and importance of clinical trial registries and results databases

The clinical research enterprise generates scientific data through the conduct of experiments in human volunteers. As described in other chapters, a key objective of the clinical research enterprise is obtaining generalizable knowledge to advance the medical evidence base and to inform clinical decision making. Public access to information about individual research studies and their results is necessary to achieve this objective, ethically, legally, and scientifically. Several recent high-profile cases indicate that lack of systematic access to information about ongoing and completed clinical studies can lead to a skewed view of available evidence regarding the safety or effectiveness of a medical intervention for a particular use.

This chapter focuses on trial registries and results databases that are designed to make summary clinical research information publicly accessible and available. Although such databases serve multiple goals and audiences, one key goal is to mitigate the effects of bias from incomplete disclosure of clinical trials and their results by promoting full disclosure throughout the trial life-cycle. The chapter also review recent trends and upcoming issues in promoting increased transparency to support public health and the scientific process. ClinicalTrials.gov (http://clinicaltrials.gov), established and maintained by the National Library of Medicine (NLM) at the National Institutes of Health (NIH), is used throughout this chapter as a case study. It is the world's largest publicly available clinical trials database.